Balance Sheet Parentheticals - USD ($) shares in Thousands, $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accumulated depreciation and amortization, property and equipment	$ 5,815	$ 61,741
Preferred stock, par value per share (usd per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000	5,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value per share (usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized	225,000	225,000
Treasury stock, shares	793	407
Common Stock
Common stock, shares issued	142,289	106,679